Car2Go, the Daimler car-sharing service, is officially launching in D.C. and will begin service on March 24 with a fleet of approximately 200 vehicles, 20 times larger than the fleet Herz On Demand debuted with earlier this month and about a fourth of the size of Zipcar's fleet accumulated over the past decade. Both Hertz On Demand and Car2Go join Zipcar to provide car-sharing services in the District.

I noticed this morning that @Car2GoDC began following about 600 followers seemingly overnight on Twitter. By this afternoon, the number rose to more than 900. Why might that be? I sent Car2Go spokesperson Katie Stafford a note asking what was up. Sure enough, this afternoon she told me that it's official. Car2Go, its U.S. operations based in Austin, Texas, has successfully finished negotiating operational details with the District Department of Transportation and will launch formally in a matter of weeks. You may have already seen some of their cars out on the street not long ago as part of testing.

"On behalf of car2go, I'm pleased to announce we are launching an entirely new way of car-sharing in Washington, D.C." Stafford told me.

Today begins free Car2Go registration, with an opportunity to grab some free driving time. Register at Car2Go's D.C. site with the promotion code "capital" to waive the $35 application fee and receive 30 minutes of free driving time. The rates are 38 cents a minute, $13.99 an hour, and $72.99 a day.

What's remarkable about Car2Go is the flexibility and concept of urban mobility. It's the only car-sharing service I've encountered that charges by the minute. Their tiny 41-miles-a-gallon blue-and-white Fortwos are intended for casual point-to-point trips within the Car2Go designated operating area of the city. The staff has set up a home base at 1710 Rhode Island, NW, and in addition to a Twitter account has kicked off a Facebook page.

Car2Go today announces that you'll be able to access its vehicles "via a smartphone app, via the car2go vehicle finder on the car2go website, by calling the customer call center, or simply by finding an available car on the street." The convenience befits a city that has grown accustomed to smartphone apps like Taxi Magic and Spotcycle as well as technologically focused companies like Uber in recent months.

70,000 members worldwide belong to Car2Go, which in the U.S., operates in Austin and San Diego, and now as of March, Washington, D.C. and Portland, Oregon. Portland's service is expected to begin a week after D.C.'s on March 31. Car2Go also hopes to feature a fleet of 200 in Portland.

Expect to learn more soon. The District's car-sharing market is evolving fast.